Probability with Dice
Project Overview: Roll a die dozens of times, record the results in Google Sheets, build a chart, and discover the difference between what probability predicts and what actually happens in real life.
Materials:
Computer with internet access
A 6-sided dice
Instructions:
A standard die has 6 faces, each equally likely to land face up. The probability of rolling any single number is 1 out of 6, or about 16.7%. If you roll 60 times, you would theoretically expect each number to appear about 10 times. Note this down!! This is your benchmark.
Go to sheets.google.com and create a new spreadsheet. Name it "Dice Probability Experiment." In cells A1 through D1, add these headers: Die Face, Tally, Experimental %, Theoretical %. In cells A2 through A7, type the numbers 1 through 6. In column D (D2 through D7), type 16.7 for each row. This is the theoretical probability percentage for each face.
Click on cell F1 and type "Roll Log." This is where you will record every single roll as you go. You will enter each result in cells F2 through F61: one cell per roll, 60 rolls total.
Roll your die 60 times. After each roll, type the result into the next empty cell in your roll log (starting at F2).
In cell B2, type this formula to count how many times you rolled a 1: =COUNTIF($F$2:$F$61, A2)
This tells Google Sheets: "count how many cells in my roll log match the die face in column A." Drag the formula down from B2 to B7 to tally all six faces automatically.
In cell C2, type this formula to convert your tally into a percentage: =ROUND(B2/60*100, 1)
This divides your tally by the total number of rolls and multiplies by 100 to get a percentage, rounded to 1 decimal place. Drag it down from C2 to C7 to fill all six rows.
Select columns A through D (rows 1–7). Click Insert → Chart. Choose a "Grouped bar chart" or "Column chart." This will show your experimental results and theoretical probability side by side for each die face. Add a title: "Experimental vs. Theoretical Probability."
Look at your chart. Which number came up most often? Which came up least? How close were your experimental percentages to the theoretical 16.7%? Are any numbers surprisingly far off?
